Evanston’s lights are shining more brightly now than at almost any other time in the last decade, thanks to the diligence and persistence of the City’s Energy Commission.
A March 31, 1999, RoundTable article by Beth Demes cited a study by Stanley Consultants Inc., commissioned by the City that “confirms that residents here suffer five times more power outages than an average Northern Illinois customer. These outages often last 5 to 20 minutes longer than in other ComEd communities.”
The Stanley Report “revealed that nearly half of the electrical feeder lines are operating near maximum capacity, and [many] of the rest are at 50 to 75 percent of capacity. This becomes a problem when these lines are needed to back up outages on other feeders and as electrical demand in general continues to increase.” The 1999 article said the Stanley Report recommended “system upgrade, better line protection (from wind, trees and wildlife), and improved notification systems,” Ms. Demes wrote.
These and other recommendations formed the basis of negotiations between the City and ComEd that, still in 2008, are ongoing. As long as squirrels dance and tree branches sag on power lines, as long as thunderstorms and lightning strikes plague the Evanston skies, there will be interruptions in electric service. But now, after nine years of talks that began as negotiations and continue as collaborations, fewer feeders are loaded at greater than 90 percent of capacity, and outages are much less frequent and of shorter duration.
Dennis Marino, interim community development director of the City, said there has been “dramatic improvement” since the 1990s. “Relative to other ComEd systems, Evanston continues to do better,” he said.
A few years ago the City of Evanston declined to sign the Northwest Municipal Franchise agreement – between ComEd and several municipalities in the area – under which ComEd would provide electricity to the City for decades. Instead, Evanston opted for several short-term extensions of its original franchise and demanded improved service and accountability as prerequisites to any long-term commitment, Mr. Marino said. The series of short-term franchise agreements set up a forum for discussing issues, particularly the frequency and duration of power outages in the community, he added.
A Brief History of the Franchise
ComEd is strictly a power-delivery company these days; the company no longer produces electricity. (Its parent company, Excelon, owns an independent power-producing company.) In exchange for its ability to use the City’s public rights-of-way to deliver the electricity, ComEd provides free electricity to City buildings that do not charge money for services – to the Civic Center, for example, and the libraries, but not to any of the recreation centers. To supply the free electricity, as well as power for residential customers (who have not yet attracted retail power-suppliers), the state conducts power procurement.
The 1950s-era franchise agreement between an energy-producing ComEd and the City expired several years ago, and the City has negotiated several extensions, most of them of about three years’ duration, in preparation for a longer agreement. As part of this preparation, the City’s negotiating team – the Technical Review Group (TRG) – meets regularly with ComEd representatives to discuss areas of concern, said Mr. Marino.
The reliability reports ComEd submits regularly to the City are generally prefaced – as was the Oct. 31 report – with the sentences “Improving reliability in Evanston is a top priority for ComEd” and “ComEd is committed to working with Evanston’s Technical Review Group to follow through on plans that meet Evanston’s reliability needs.”
Power Interruptions
One of the tasks of the City’s Energy Commission is to monitor the reliability of ComEd. Mr. Marino, who serves as the City staff member on the commission, said the commission “looks at the outages that are repetitive and focuses on the causes. … Of course, we look at storm-related outages differently from other outages. Trees, for example, present a different kind of issue. But the response time – even in storms – is better than it has been.”
According to a report created by Business Performance & Measurements for ComEd, for the first nine months of this year, the average number of power interruptions per customer in Evanston was 1.31, compared to 1.41 for ComEd customers in Northern Illinois. The average length of a power interruption in Evanston was 116 minutes, as compared to 179 minutes for other ComEd customers. These figures included the power interruptions caused by the storm of Aug. 4.
From January through September 2008, the eight leading causes of power interruptions were trees (43), underground failures (40), malfunctions (21), animal-related (14), “other” (14), “intentional, unscheduled,” weather (11, including four from lightning), broken fuse link (5) and “contamination” (4).
Examples of some of the more severe interruptions noted in the report include an 11-minute outage on April 17, caused by squirrels and affecting more than 1,000 customers. An outage on June 29 that lasted 334 minutes and affected 1,554 customers was “overhead-equipment related.”
A 445-minute tree-related outage on June 6 affected 319 customers; another tree-related outage lasted 1,338 minutes but affected only one customer. Another tree-related outage, this one on Sept. 8, lasted 308 minutes and affected 760 customers, according to the report.
To minimize power interruptions from trees, ComEd follows a four-year cycle of inspecting and trimming trees on parkways. The schedule provided by ComEd shows that most of 2009’s tree activity will be inspections, with some scheduled trimming in January, as well as some to be completed in December of this year.
Underground Equipment Failures
Underground failure – the cause of a 93-minute outage on May 14 that affected 2,637 customers and of a 177-minute outage on July18 that affected 811 customers, as examples in the report – has aroused the concern of some members of the Energy Commission.
William Siegfriedt, vice chair, has served on the City’s Energy Commission since 2004, told the RoundTable he would like to see ComEd conduct an inventory of its buried cables and identify the type, age and repair history of each. “ComEd has done a great job of eliminating overhead outages,” he said, “so I think if we’re going to continue to improve, we need to look at the underground cables.”
There are three ways to bury cables, Mr. Siegfriedt said, and the “burial mode provides an indication of the potential types of failure.”
If they are heavily insulated, cables may be buried directly. Alternatively, cables can be encased in a buried pipe. The third approach, and one that Mr. Siegfriedt acknowledges is more costly than either of the other two methods, is to encase pipes in underground concrete and put the cables in those pipes. These duct banks would run from manhole to manhole – about 750 feet, he said – which would allow access for repair. “Industrial plants do this [run the cable in duct banks] all the time, because they typically have the money to do it.”
Another indicator of potential cable failure is the era in which it was installed. Mr. Siegfriedt says the older buried cables give him less concern than those buried more recently. “What they did in the 1920s was fabulous; what they did in the 70s – not so fabulous,” he said.
Mr. Marino appears to agree about the desirability of an inventory of ComEd’s underground cables. “We need to know which cables are part of the underground system,” he said.
“ComEd’s stance is, ‘We will fix buried cable only when it fails,’” Mr. Siegfriedt said. “We want them to try to prevent outages.” Even though this is a new area of negotiation between the City and ComEd, Mr. Siegfriedt seems upbeat about the eventual outcome. “It might take one or two meetings [for them to come around],” he said. Development of the inventory will likely require several years, he said.